We had a hard winter in Vancouver and my Bay tree had quite a severe frost damage. Most of its outer layer of leaves are brown and gone. I left it alone until now (early June) and see if there's signs of recovery. This week, I notice small (tiny) buds are forming and wonder if it is time for me to prune it back, or if it is still too early to prune it back.
If you want to keep as much live wood as possible, leave it for another month or so, when seeing what's live and what isn't will be easier. But no real harm in cutting back now, losing a little bit of live wood wouldn't be a serious danger to it. It would even regrow from a coppiced stump, just take longer to regrow to full size.
